A recent update on the Firefox browser to 56.0.1 has created a problem on certain websites (e.g. https://www.theguardian.com/uk). When accessing them, the screen goes blank, then a SteamVR window appears saying (unresponsive) firefox.exe
This is due to the new WebVR standard being implemented in Firefox, and certain adverts on these websites try to launch a VR session if you have a HMD attached.
Given that it's an annoyance, here is a quick tip to fix it.
1) Launch Firefox.
2) In the navigation bar type ABOUT:CONFIG and press return. This will launch an advanced configuration tool.
3) Once you have got past the warning, go to the search bar at the top on the config tool and type DOM.VR.OPENVR.ENABLED
4) Double click on the entry and it will show as modified meaning that it's been disabled.
5) Quit and relaunch Firefox.
Et voila, no more blank screens and weird error boxes.
18 October 2017